Arctostaphylos uva ursi (L.) Spreng. · herb
Evidence tier: weak
Reduces urinary tract symptoms in benign prostate enlargement and recurrent UTIs through antimicrobial arbutin metabolites excreted in the urine
A prodrug that only works downstream. Arbutin, a hydroquinone glycoside making up 5 to 15% of the dried leaf, is hydrolysed to hydroquinone, which is excreted in the urine and is bacteriostatic against E. coli and other urinary pathogens in vitro. The catch, and it is a large one, is that hydroquinone's antibacterial activity is pH dependent and is described as requiring alkaline urine, which normal urine is not. That mechanism is confirmed in the test tube and never demonstrated to deliver a clinical cure in the two trials that looked for one, which is the most likely explanation for why a plausible mechanism produced negative trials.
Weak, and weak in the worst way: not understudied, but studied and failed. Two proper randomised trials have tested uva ursi for uncomplicated urinary tract infection in women, and neither supports it. ATAFUTI (Moore, Clinical Microbiology and Infection 2019) found NO evidence of an effect of uva ursi on symptom severity and no reduction in antibiotic consumption (39.9% versus 47.4% on placebo), while the ibuprofen arm of the same factorial trial did reduce antibiotic use. REGATTA (Gagyor, Clinical Microbiology and Infection 2021) randomised 398 women to uva ursi (105 mg arbutin, three tablets twice daily for five days) against a single 3 g dose of fosfomycin. Uva ursi did cut antibiotic courses by 63.6%, which is a real finding, but the total symptom burden was 136.5% of the fosfomycin group, and there were EIGHT cases of pyelonephritis and three of fever on uva ursi versus two pyelonephritis and none on fosfomycin. The authors' conclusion is the one that matters: the higher occurrence of pyelonephritis and fever argued against uva ursi as initial treatment in general. An unmanaged UTI can ascend to the kidney, and in this trial it did so four times as often. The regulator never claimed more than tradition. The EMA HMPC monograph on Arctostaphylos uva ursi (L.) Spreng., folium is TRADITIONAL USE ONLY, for relief of symptoms of mild recurrent lower urinary tract infections such as burning sensation during urination and/or frequent urination IN WOMEN, after serious conditions have been excluded by a doctor, exclusively based upon long standing use. The EMA states plainly: not to be used for more than one week. Use in men is not recommended. Use under 18 is not recommended. Contraindicated in kidney disorders. On hydroquinone, be precise rather than alarming: the concern that drives the one week cap is theoretical genotoxicity and carcinogenicity, not a documented human injury, and a published risk assessment found that at the recommended daily dose free hydroquinone reaches roughly 11 micrograms per kg bodyweight per day in urine, well below the 100 microgram per kg permitted daily exposure. The one week limit is a precaution, and it is still binding.
EMA traditional use, female adults: dry extract at a dose corresponding to 100 to 210 mg of hydroquinone derivatives calculated as anhydrous arbutin, two to four times daily, giving 200 to 840 mg daily. Or herbal tea, 1.5 to 4 g of the comminuted leaf in 150 ml boiling water, two to four times daily, maximum 8 g daily. NOT TO BE USED FOR MORE THAN ONE WEEK. Not recommended in men, or under 18.
Take 400 to 840mg of standardised extract (standardised to 20% arbutin) twice daily for 5 to 7 days only. Do not use for more than 5 consecutive days or more than 5 times per year. Not for use in kidney disease or pregnancy.
Onset: ~3 days
SHORT-TERM ONLY (7 to 10 days max, 4 courses/year). Hydroquinone is hepatotoxic and potentially carcinogenic with prolonged exposure. Urine must be alkaline for efficacy (avoid acidic foods, vitamin C). Avoid in pregnancy, kidney disease, liver disease, children under 12. Urine may turn greenish brown.
Pregnancy: avoid
Breastfeeding: avoid
Used for at least 1,000 years in European and Native American herbal medicine for urinary tract infections. Referenced in 13th century Welsh herbalism. One of the most commonly used herbs for urinary health in traditional Western herbalism. Contains arbutin, which converts to hydroquinone in the urinary tract, an antimicrobial compound.
Active compounds: arbutin, methylarbutin, gallotannins, ellagitannins, hyperoside, ursolic acid
Remedies using Uva Ursi · Browse by body system · Check it against what you take
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